Conformal lining layers for damascene metallization

• US 20040130029A1
• Filed: 12/15/2003
• Published: 07/08/2004
• Est. Priority Date: 10/15/1999
• Status: Active Grant

• Current Assignee: Ernst H.A. Granneman, Ivo Raaijmakers, Kai-Erik Elers, Pekka J. Soininen, Suvi P. Haukka, Yille A. Saanila
• Original Assignee: Ernst H.A. Granneman, Ivo Raaijmakers, Kai-Erik Elers, Pekka J. Soininen, Suvi P. Haukka, Yille A. Saanila
• Inventors: Soininen, Pekka J., Raaijmakers, Ivo, Elers, Kai-Erik, Haukka, Suvi P., Granneman, Ernst H.A., Saanila, Yille A.
• Granted Patent: US 7,102,235 B2
• Time in Patent Office: Days
• US Class Current: 257/758
• CPC Class Codes: C23C 16/0272 Deposition of sub-layers, e.g. to promote the adhesion of the main coating
• CPC Class Codes: C23C 16/045 Coating cavities or hollow spaces, e.g. interior of tubes; Infiltration of porous substrates
• CPC Class Codes: C23C 16/08 from metal halides
• CPC Class Codes: C23C 16/14 Deposition of only one other metal element
• CPC Class Codes: C23C 16/32 Carbides
• CPC Class Codes: C23C 16/34 Nitrides C23C16/303 takes precedence
• CPC Class Codes: C23C 16/44 characterised by the method of coating C23C16/04 takes precedence
• CPC Class Codes: C23C 16/45525 Atomic layer deposition [ALD]
• CPC Class Codes: C23C 16/45534 Use of auxiliary reactants other than used for contributing to the composition of the main film, e.g. catalysts, activators or scavengers
• CPC Class Codes: C23C 16/45536 Use of plasma, radiation or electromagnetic fields
• CPC Class Codes: C30B 25/02 Epitaxial-layer growth
• CPC Class Codes: C30B 29/02 Elements
• CPC Class Codes: C30B 29/36 Carbides
• CPC Class Codes: H01L 21/28562 Selective deposition
• CPC Class Codes: H01L 21/7681 involving one or more buried masks
• CPC Class Codes: H01L 21/76814 post-treatment or after-treatment, e.g. cleaning or removal of oxides on underlying conductors
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76846 Layer combinations
• CPC Class Codes: H01L 21/76873 for electroplating
• CPC Class Codes: H01L 23/5226 Via connections in a multilevel interconnection structure
• CPC Class Codes: H01L 23/53223 : Additional layers associated with aluminium layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 23/53238 : Additional layers associated with copper layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 23/53242 : the principal metal being a noble metal, e.g. gold
• CPC Class Codes: H01L 23/53252 : Additional layers associated with noble-metal layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 23/5329 : Insulating materials
• CPC Class Codes: H01L 23/53295 : Stacked insulating layers
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 : Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

Method and structures are provided for conformal lining of dual damascene structures in integrated circuits. Trenches and contact vias are formed in insulating layers. The trenches and vias are exposed to alternating chemistries to form monolayers of a desired lining material. Exemplary process flows include alternately pulsed metal halide and ammonia gases injected into a constant carrier flow. Self-terminated metal layers are thus reacted with nitrogen. Near perfect step coverage allows minimal thickness for a diffusion barrier function, thereby maximizing the volume of a subsequent filling metal for any given trench and via dimensions.

Claims

1. A dual damascene structure in an integrated circuit, comprising;

a trench formed in an insulating layer;

at least one contact via extending from a floor of the trench downwardly to a conductive element below; and

a conductive lining layer along surfaces of the trench and the contact via, the lining layer having a maximum thickness of less than about 100 Å and

a step coverage of greater than about 90%.

2. The structure of claim 1, further comprising a metal integrally filling the lined trench and contact via.

3. The structure of claim 1, wherein the conductive lining layer comprises a metal nitride layer.

4. The structure of claim 3, wherein the metal nitride layer directly contacts the insulating layer and the conductive element.

5. The structure of claim 4, wherein the conductive element comprises a copper line.

6. The structure of claim 3, wherein the metal nitride layer comprises titanium nitride.

7. The structure of claim 3, wherein the metal nitride layer comprises tungsten nitride.

8. The structure of claim 3, wherein the metal nitride layer comprises tantalum nitride.

9. The structure of claim 1, wherein the lining layer has a thickness of between about 20 Å

and 100 Å

.

10. The structure of claim 1, wherein the lining layer has a step coverage of greater than about 93%.

11. The structure of claim 10, wherein the lining layer has a step coverage of greater than about 97%.

12. The structure of claim 1, wherein the trench has a width of less than about 0.35 μ

m.

13. The structure of claim 12, wherein the trench has a width of less than about 0.25 μ

m.

14. The structure of claim 1, wherein the contact via has a width of less than about 0.35 μ

m.

15. The structure of claim 1, wherein the contact via has a width between about 0.05 μ

m and 0.25 μ

m.

16. A metal structure in an integrated circuit, the structure comprising:

a metal runner in an upper insulating layer;

a metal contact extending integrally from the metal runner through a lower insulating layer; and

a metal nitride layer interposed between the upper insulating layer and the metal runner and interposed between the lower insulating layer and the metal contact, the metal nitride layer having a maximum thickness of no more than about 200 Å

on any surface.

17. The metal structure of claim 16, wherein the metal nitride layer has a thickness between about 20 Å

and 110 Å

.

18. The metal structure of claim 16, wherein the metal nitride layer has a thickness on a bottom surface and sidewall of the metal contact that is at least about 93% of a maximum thickness of the metal nitride layer.

19. The metal structure of claim 16, wherein the metal and the metal contact comprise the same metal.

20. The metal structure of claim 19, wherein the metal is copper.

21. The metal structure of claim 19, wherein the metal is aluminum.

22. The metal structure of claim 16, further comprising a seed layer overlying the conductive lining layer.

23. The metal structure of claim 22, wherein the seed layer comprises tungsten.

24. The metal structure of claim 22, wherein the seed layer comprises copper.

25. The metal structure of claim 16, wherein the metal contact has a depth to width ratio of greater than about 2:

1.

26. The metal structure of claim 25, wherein the depth to width ratio is greater than about 8:

1.